Add apt-offline to xubuntu packageset

[Stephen Michael Kellat]

Hello.  It was decided during Xubuntu's planning for 13.10 to add apt-offline to the disc seed.  Could apt-offline please be added to our packageset so that action could then be taken on clearing https://code.launchpad.net/~skellat/ubuntu-seeds/xubuntu.saucy-aptoffline-addition followed by https://bugs.launchpad.net/ubuntu/+source/xubuntu-meta/+bug/1183638 perhaps?

Thank you for your patience and consideration.

Stephen Michael Kellat